Overdrive problem

[Fearlessfozz]

Please bear with me as I’m new to this forum and getting to know my TR6. 

Mom having a problem with the overdrive unit.  During a trip a couple of weeks ago it seemed that the overdrive unit would not disengage to the point where I was going uphill and it gave the impression that the clutch was slipping!  I’ve tried switching the overdrive unit on with the ignition switch turned on ( engine not running) and in third gear. I could not hear the solenoid but the petrol pump slowed up a little which seemed to indicate that there was a draw on the current. 

Can anyone offer any fault finding advice please. 

 

[Mike C]

When the overdrive comes in you should see a drop in the revs on the tachometer. Does this happen when you switch it on and off.

If  the tacho doesn't  change  I'd check the solenoids moving and also check the gearbox oil level while I'm under the car. 

The overdrive in top gear imposes maximum loads on the clutch, so if it's a bit weak this is when it will slip.

 

 

 

Edited October 31, 2018 by Mike C

[Fearlessfozz]

Hi Mike C, 

Yes the revs we’re dropping but the symptom appears to be the overdrive not disengaging. However I will check the gearbox oil level. 

Thanks 

[RogerH]

Hi Fozz,

              if the OD is not disengaging then do NOT reverse the car. The OD may fracture its casing.

Take the car for a drive on  a flat road doing apprx 60mph.

In 4th gear select OD 0 the revs should drop from about 3000rpm to 2500rpm.

Now deselect OD the revs should return to 3000rpm.

 

Roger

[Fearlessfozz]

Hi Roger, 

thanks for info. I forgot to mention that when I had the problem I switched the ignition off and the next day all was well but I did not use the overdrive rather than risk it. 

Ian 

[Mike C]

I'm assuming you have a type A like mine.

If it reset overnight and the electrical components work correctly, the operating valve could have its restrictor blocked. But I'd check everything else before I started working on the innards of the OD.

[Fearlessfozz]

On 11/1/2018 at 10:01 PM, Mike C said:

I'm assuming you have a type A like mine.

If it reset overnight and the electrical components work correctly, the operating valve could have its restrictor blocked. But I'd check everything else before I started working on the innards of the OD.

Hi, I just wanted to clarify that I have a J type overdrive.  So at the weekend, had the use of a friends pit, eventually got the gearbox filler plug unscrewed to reveal a trickle of oil, so no problem there. 

When switching the overdrive switch on the column there is no noise coming from the solenoid. I then disconnected the solenoid wires and fitted a bulb across the terminals. I selected third gear and when operating the column switch the bulb illuminated. So there didn’t appear to be an electrical problem. To also confirm when selecting first or second gear the build would not illuminate, proving that the gearbox switches are working ok. 

Do I now assume that I have a faulty solenoid or is there something I’m missing? 

Fozzy 

[dingle]

The solenoid on the J type makes very little noise compared to the A type. 

Berry

[Mike C]

Look's like the solenoid, Buckeye has a bit to say on testing J type actuation:

https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&ved=0ahUKEwicsYOTn77eAhWZfH0KHTniD5UQMwg8KAEwAQ&url=http%3A%2F%2Fwww.buckeyetriumphs.org%2Ftechnical%2Fjod%2FJOD4%2FJOD4.htm&psig=AOvVaw2SfwjxsXZD5KRyAKMcwRQt&ust=1541541344394394&ictx=3&uact=3

Edited November 5, 2018 by Mike C

[Fearlessfozz]

Thanks everyone I’ll let you know the outcome.